A network element with multiple interfaces can route data from one network to another network by receiving the data, analyzing the data, and deciding which interface to transmit the data and which next hop rewrite to perform on the packet. In particular, if the data is stored in a packet, the network element determines the transmission interface by analyzing a destination address stored in the packet header. The network element lookups a match for the destination address in a forwarding table to determine both which interface the network element will transmit the packet and which next hop rewrite to perform. The forwarding information is stored in a forwarding table. Each entry in the forwarding table includes an address subnet and an interface and a next hop rewrite, which is a next hop. The subnet is a subdivision of a network and is represented by a range of network addresses, or addresses.
Various structures can be used to store entries for a forwarding table. For example, a longest prefix match table can be used to store the forwarding table entries. In this example, the network element performs a lookup to determine which of the entries match using the longest prefix match table. Longest prefix match tables can be implemented in a few different ways which are sometimes expensive in terms of chip area and power.